<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <input type="file" class="file">
  <button class="upload">上传文件</button>
  <script>
    const uploadBtn = document.querySelector(".upload")
    uploadBtn.onclick = function () {
      const xhr = new XMLHttpRequest()

      xhr.onload = function () {
        console.log(xhr.response)
      }

      xhr.onprogress = function (event) {
        console.log(event)
      }

      xhr.responseType = "json"
      xhr.open("post", "http://123.207.32.32:1888/02_param/upload")
      // 表单
      const fileEl = document.querySelector(".file")
      const file = fileEl.files[0]
      
      const formData = new FormData()
      formData.append("file", file)

      xhr.send(formData)
    }

  </script>
</body>

</html>